Proximity services path selection and switching

ABSTRACT

A user equipment (UE) is configured to connect to a next generation nodeB (gNB) and further UE. The UE determines that a triggering event has occurred, wherein the triggering event is based on a set of proximity services (ProSe) path selection and switching (PSS) policies, transmits a setup or update request to a direct discovery name management function (DDNMF) of a 5G core network, receives UE-specific policies based on the set of ProSe PSS policies, and switches from one of a PC5 interface or a Uu interface to another one of the PC5 interface or the Uu interface.

BACKGROUND

Proximity services (ProSe) includes two features: (1) network-assisteddiscovery of user equipment (UEs) that wish to communicate with eachother and are in close proximity to one another; and (2) facilitation ofdirect communication between UEs both with and without input from thenetwork. Direct communication means a radio connection is establishedbetween the UEs without transmitting information via the network. As aresult, network resources are saved and public safety communication inareas outside network coverage may be enabled.

In 5G new radio (NR), ProSe are expected to be an important system wideenabler to support various applications and services both in commercialand public safety domains. As an example, 3GPP TR 22.842 identifiedemerging Network-controlled Interactive services (NCIS) that share somecommonality of requirements with public safety services andapplications. For either form of services, supporting the requirementsfor throughput, latency, reliability or other service requirementsrequires employing path selection.

SUMMARY

Some exemplary embodiments include a computer readable storage mediumcomprising a set of instructions that when executed by a processor causethe processor to perform operations. The operations include determiningthat a triggering event has occurred, wherein the triggering event isbased on a set of proximity services (ProSe) path selection andswitching (PSS) policies, transmitting a setup or update request to adirect discovery name management function (DDNMF) of a 5G core network,receiving UE-specific policies based on the set of ProSe PSS policies,and switching from one of a PC5 interface or a Uu interface to anotherone of the PC5 interface or the Uu interface.

Other exemplary embodiments relate to a user equipment (UE) having atransceiver and a processor. The transceiver is configured to connect toa next generation nodeB (gNB) and further UE. The processor isconfigured to determine that a triggering event has occurred, whereinthe triggering event is based on a set of proximity services (ProSe)path selection and switching (PSS) policies, transmit a setup or updaterequest to a direct discovery name management function (DDNMF) of a 5Gcore network, receive UE-specific policies based on the set of ProSe PSSpolicies, and switch from one of a PC5 interface to connect with thefurther UE or a Uu interface to connect to the gNB to another one of thePC5 interface or the Uu interface.

Still further exemplary embodiments are related to an integrated circuitconfigured for use in a user equipment (UE). The integrated circuitincludes circuitry configured to determine that a triggering event hasoccurred, wherein the triggering event is based on a set of proximityservices (ProSe) path selection and switching (PSS) policies, circuitryconfigured to transmit a setup or update request to a direct discoveryname management function (DDNMF) of a 5G core network, circuitryconfigured to receive UE-specific policies based on the set of ProSe PSSpolicies, and circuitry configured to switch from one of a PC5 interfaceto connect with another UE or a Uu interface to connect to a nextgeneration NodeB (gNB) to another one of the PC5 interface or the Uuinterface.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an exemplary network arrangement according to variousexemplary embodiments.

FIG. 2 shows an exemplary UE according to various exemplary embodiments.

FIGS. 3A and 3B show exemplary network architectures for proximityservices according to various exemplary embodiments.

FIG. 4 shows a signaling diagram for policy control function(PCF)-created path selection and switching policies initiated by anapplication function (AF) according to various exemplary embodiments.

FIG. 5 shows a signaling diagram for network-assisted path selection andswitching according to various exemplary embodiments.

FIG. 6 shows a signaling diagram for application-assisted path selectionand switching according to various exemplary embodiments.

FIG. 7 shows a signaling diagram for a UE-requested policy provisioningupdate according to various exemplary embodiments.

FIG. 8 shows a signaling diagram for a networks data analytics function(NWDAF)-based path selection and switching analytics and predictionsaccording to various exemplary embodiments.

DETAILED DESCRIPTION

The exemplary embodiments may be further understood with reference tothe following description and the related appended drawings, whereinlike elements are provided with the same reference numerals. Theexemplary embodiments relate to proximity services (ProSe) and moreparticularly, selection and switching of communication paths.

The exemplary embodiments are described with regard to a UE. However,the use of a UE is merely for illustrative purposes. The exemplaryembodiments may be utilized with any electronic component that mayestablish a connection with a network and is configured with thehardware, software, and/or firmware to exchange information and datawith the network. Therefore, the UE as described herein is used torepresent any electronic component.

The exemplary embodiments are also described with regard to a networkthat includes 5G NR radio access technology (RAT). However, reference toa 5G NR network is merely provided for illustrative purposes. Theexemplary embodiments may be utilized with any network that implementsProSe or an equivalent technology. Therefore, the 5G NR network asdescribed herein may represent any network that includes the ProSefunctionalities.

To improve the support of ProSe functionality, the appropriate directcommunication path (or interface) may be selected by the UE based on apredetermined policy which may be configured by a network operator orassisted by the network when available. Current UE route selectionpolicy (URSP) rules do not identify which service(s) apply to aparticular UE. As such, the UE is left to determine for itself which areapplicable. An issue that remains unaddressed with ProSe is how a 5Gsystem (5GS) can support direct path selection and switching by the UE.

According to exemplary embodiments, an application function (AF) of the5G core network may initiate the creation of ProSe path selection andswitching (PSS) policies by a policy control function (PCF) also of the5G core network. These policies guide the selection and switching by theUE of a communication path (Uu and/or PC5). In some embodiments, theswitching between a Uu interface (universal mobile telecommunicationssystem air interface between the UE and radio access network) and a PC5interface (UE to UE interface) may be triggered or initiated by thenetwork due to satisfying one or more of the PSS policies or due to anapplication triggering event. In some embodiments, the switching betweenUu and PC5 may be triggered or initiated by the UE due to thesatisfaction of one or more of the PSS policies.

FIG. 1 shows an exemplary network arrangement 100 according to variousexemplary embodiments. The exemplary network arrangement 100 includes afirst UE 110A, a second UE 110B, and a third UE 110C (collectively theUEs 110). It should be noted that any number of UEs may be used in thenetwork arrangement 100. Those skilled in the art will understand thatthe UEs 110 may be any type of electronic component that is configuredto communicate via a network, e.g., mobile phones, tablet computers,desktop computers, smartphones, phablets, embedded devices, wearables,Internet of Things (IoT) devices, etc. It should also be understood thatan actual network arrangement may include any number of UEs being usedby any number of users. Thus, the example of a single UEs 110 is merelyprovided for illustrative purposes.

The UEs 110 may be configured to communicate with one or more networks.In the example of the network configuration 100, the networks with whichthe UEs 110 may wirelessly communicate are a 5G New Radio (NR) radioaccess network (5G NR-RAN) 120, an LTE radio access network (LTE-RAN)122 and a wireless local access network (WLAN) 124. However, it shouldbe understood that the UEs 110 may also communicate with other types ofnetworks and the UEs 110 may also communicate with networks over a wiredconnection. Therefore, the UEs 110 may include a 5G NR chipset tocommunicate with the 5G NR-RAN 120, an LTE chipset to communicate withthe LTE-RAN 122 and an ISM chipset to communicate with the WLAN 124.

The 5G NR-RAN 120 and the LTE-RAN 122 may be portions of cellularnetworks that may be deployed by cellular providers (e.g., Verizon,AT&T, Sprint, T-Mobile, etc.). These networks 120, 122 may include, forexample, cells or base stations (Node Bs, eNodeBs, HeNBs, eNBS, gNBs,gNodeBs, macrocells, microcells, small cells, femtocells, etc.) that areconfigured to send and receive traffic from UEs that are equipped withthe appropriate cellular chip set. The WLAN 124 may include any type ofwireless local area network (WiFi, Hot Spot, IEEE 802.11x networks,etc.).

The UEs 110 may connect to the 5G NR-RAN 120 via the gNB 120A. The gNB120A may be configured with the necessary hardware (e.g., antennaarray), software and/or firmware to perform massive multiple in multipleout (MIMO) functionality. Massive MIMO may refer to a base station thatis configured to generate a plurality of beams for a plurality of UEs.During operation, the UEs 110 may be within range of a plurality ofgNBs. Thus, either simultaneously or alternatively, the UEs 110 may alsoconnect to the 5G NR-RAN 120 via the gNB 120B. Reference to two gNBs120A, 120B is merely for illustrative purposes. The exemplaryembodiments may apply to any appropriate number of gNBs. Further, theUEs 110 may communicate with the eNB 122A of the LTE-RAN 122 to transmitand receive control information used for downlink and/or uplinksynchronization with respect to the 5G NR-RAN 120 connection.

Those skilled in the art will understand that any association proceduremay be performed for the UEs 110 to connect to the 5G NR-RAN 120. Forexample, as discussed above, the 5G NR-RAN 120 may be associated with aparticular cellular provider where the UEs 110 and/or the user thereofhas a contract and credential information (e.g., stored on a SIM card).Upon detecting the presence of the 5G NR-RAN 120, the UEs 110 maytransmit the corresponding credential information to associate with the5G NR-RAN 120. More specifically, the UEs 110 may associate with aspecific base station (e.g., the gNB 120A of the 5G NR-RAN 120).

In addition to the networks 120 and 122 the network arrangement 100 alsoincludes a cellular core network 130. The cellular core network 130 maybe considered to be the interconnected set of components that managesthe operation and traffic of the cellular network. In this example, thecomponents include a session management function (SMF) 131, an accessand mobility management function (AMF) 132, a user plane function (UPF)133, a policy control function (PCF) 134, an application function (AF)135, a direct discovery name management function (DDNMF) 136, a networkexposure function (NEF) 137, unified data management (UDM) 138, and aunified data repository (UDR) 139. However, an actual cellular corenetwork may include various other components performing any of a varietyof different functions.

The SMF 131 performs operations related to session management (SM), UEIP address allocation and management (including optional authorization),selection and control of user plane function; configuring trafficsteering at the UPF 133 to route traffic to the proper destination,termination of interfaces toward policy control functions, controllingpart of policy enforcement and quality of service (QoS), downlink datanotification; initiating access network specific SM information sent viathe AMF 132 to the 5G NR RAN 120; and determining session and servicecontinuity (SSC) mode of a session. SM may refer to management of a PDUsession. A PDU session may refer to a PDU connectivity service thatprovides or enables the exchange of PDUs between the UEs 110 and thecellular core network 130. PDU sessions may be established upon requestby the UEs 110. Reference to a single SMF 131 is merely for illustrativepurposes; an actual network arrangement may include any appropriatenumber of SMFs, as will be discussed below.

The AMF 132 performs operations related to mobility management such as,but not limited to, paging, non-access stratum (NAS) management andregistration procedure management between the UEs 110 and the cellularcore network 130. Reference to a single AMF 132 is merely forillustrative purposes; an actual network arrangement may include anyappropriate number of AMFs.

The UPF 133 performs operations related to intra-RAT and inter-RATmobility, an external PDU session point of interconnect to the cellularcore network 130, and a branching point to support multi-homed PDUsessions. The UPF 133 may also perform packet routing and forwarding,perform packet inspection, enforce the user plane part of policy rules,lawfully intercept packets (UP collection), perform traffic usagereporting, perform QoS handling for a user plane (e.g., packetfiltering, gating, UL/DL rate enforcement), perform uplink trafficverification (e.g., service data flow (SDF) to QoS flow mapping),transport level packet marking in the uplink and downlink, and downlinkpacket buffering and downlink data notification triggering. Reference toa single UPF 133 is merely for illustrative purposes; an actual networkarrangement may include any appropriate number of UPFs.

The PCF 134 performs operations related to the control plane such as,but not limited to, managing policy rules for control plane functionsincluding network slicing, roaming and mobility management. Reference toa single PCF 134 is merely for illustrative purposes; an actual networkarrangement may include any appropriate number of PCFs.

The AF 135 (also referred to herein as “ProSe AF 135”) performsoperations related to application influence on traffic routing, accessto a network cloud engine (NCE), and interaction with the policyframework for policy control. The NCE may be a mechanism that allows thecellular core network 130 and AF 135 to provide information to eachother which may be used for edge computing implementations. In suchimplementations, the network operator and third-party services may behosted close to the UEs 110 access point of attachment to achieve anefficient service delivery through reduced end-to-end latency and loadon the transport network. For edge computing implementations, thecellular core network 130 may select a UPF 133 close to the UEs 110 andexecute traffic steering from the UPF 133 to the network. This may bebased on the UE subscription data, UE location, and information providedby the AF 135. In this way, the AF 135 may influence UPF (re)selectionand traffic routing. Reference to a single AF 135 is merely forillustrative purposes; an actual network arrangement may include anyappropriate number of AFs. In some embodiments, the AF 135 may alsoserve as a ProSe application server.

The DDNMF 136 may be used for handle the mapping of ProSe applicationIDs used in ProSe direct discovery. In some embodiments, the DDNMF 136may be a standalone function within the core network 130. In someembodiments, the DDNMF 136 may be part of the application server.

The NEF 137 may provide means for securely exposing the services andcapabilities provided by 3GPP network functions for third partyapplication functions (e.g., AF 135), edge computing or fog computingsystems, etc. In some embodiments, the NEF 137 may authenticate,authorize, and/or throttle the AFs. The NEF 137 may also translateinformation exchanged with the AF 135 and information exchanged withother network functions. For example, the NEF 137 may act as atranslator between an AF-Service-Identifier and internal 5GCinformation. The NEF 137 may also receive information from other networkfunctions (NFs) based on exposed capabilities of other networkfunctions. This information may be stored at the NEF 137 as structureddata, or at a data storage using standardized interfaces. The storedinformation can then be re-exposed by the NEF 137 to other AFs, and/orused for other purposes such as analytics.

The UDM 138 may handle subscription-related information to support thenetwork entities' handling of communication sessions and may storesubscription data of the UEs 110. For example, subscription data may becommunicated between the UDM 138 and the AMF 132. The UDM may include afront end (FE), which is responsible for processing credentials,location management, subscription management, etc. Several differentfront ends may serve the same user in different transactions. The UDM-FEaccesses subscription information stored in the UDR 139 and performsauthentication credential processing, user identification handling,access authorization, registration/mobility management, and subscriptionmanagement.

The UDR 139 may store subscription data and policy data for the UDM 138and the PCF 134, and/or structured data for exposure and applicationdata (including packet flow descriptions (PFDs) for applicationdetection, application request information for multiple UEs 110) for theNEF 137. The Nudr service-based interface may be exhibited by the UDR221 to allow the UDM 138, PCF 426, and NEF 423 to access a particularset of the stored data, as well as to read, update (e.g., add, modify,delete), and subscribe to notifications of relevant data changes in theUDR 139.

FIG. 2 shows an exemplary UE 110 according to various exemplaryembodiments. The UEs 110 will be described with regard to the networkarrangement 100 of FIG. 1 . The UEs 110 may represent any electronicdevice and may include a processor 205, a memory arrangement 210, adisplay device 215, an input/output (I/O) device 220, a transceiver 225and other components 230. The other components 230 may include, forexample, an audio input device, an audio output device, a battery thatprovides a limited power supply, a data acquisition device, ports toelectrically connect the UEs 110 to other electronic devices, one ormore antenna panels, etc. For example, the UEs 110 may be coupled to anindustrial device via one or more ports.

The processor 205 may be configured to execute a plurality of engines ofthe UEs 110. For example, the engines may include a ProSe managementengine 235. The ProSe management engine 235 may perform variousoperations related to ProSe such as, for example, path selection, pathswitching, and policy update requests.

The above referenced engine being an application (e.g., a program)executed by the processor 205 is only exemplary. The functionalityassociated with the engine may also be represented as a separateincorporated component of the UEs 110 or may be a modular componentcoupled to the UEs 110, e.g., an integrated circuit with or withoutfirmware. For example, the integrated circuit may include inputcircuitry to receive signals and processing circuitry to process thesignals and other information. The engines may also be embodied as oneapplication or separate applications. In addition, in some UEs, thefunctionality described for the processor 205 is split among two or moreprocessors such as a baseband processor and an applications processor.The exemplary embodiments may be implemented in any of these or otherconfigurations of a UE.

The memory arrangement 210 may be a hardware component configured tostore data related to operations performed by the UEs 110. The displaydevice 215 may be a hardware component configured to show data to a userwhile the I/O device 220 may be a hardware component that enables theuser to enter inputs. The display device 215 and the I/O device 220 maybe separate components or integrated together such as a touchscreen. Thetransceiver 225 may be a hardware component configured to establish aconnection with the 5G NR-RAN 120, the LTE-RAN 122, the WLAN 124, etc.Accordingly, the transceiver 225 may operate on a variety of differentfrequencies or channels (e.g., set of consecutive frequencies).

FIGS. 3A and 3B show exemplary network architectures for proximityservices according to various exemplary embodiments. The networkarchitectures illustrated in FIGS. 3A and 3B are substantially similarto that of FIG. 1 , but show more details relating to proximityservices. As explained above with respect to the core network 130, FIGS.3A and 3B the network functions described above. In addition, thenetwork includes a data network name (DNN) 302 (302A or 302B) thatincludes the AF 135. The difference between the network architecture ofFIG. 3A and that of FIG. 3B is that the DDNMF 136 is a standalonenetwork function on the core network in FIG. 3A and is collocated withthe AF 135 on the DNN 302 in FIG. 3B.

Also shown in FIGS. 3A and 3B, are the UEs 110, each of which arerunning a ProSe application 304. In some embodiments, the first UE 110Amay be connected to the RAN 120 via a Uu path/interface while the secondand third UEs 110B, 110C may be connected to the first UE 110A via a PC5path/interface to establish their respective connects to the RAN 120.

In the embodiment of FIG. 3A, in which the DDNMF 136 is a standalonefunction, the DDNMF interacts with the ProSe Application Server (AF 135)via a PC2 interface and with the UE 110 via a PC3 interface. As definedin 3GPP TS 23.303, PC3 is the interface between the UE and the ProSeFunction. PC3 “is used to authorise ProSe Direct Discovery andnetwork-level ProSe Discovery requests, and perform allocation of ProSeApplication Codes/ProSe Restricted Codes corresponding to ProSeApplication Identities used for ProSe Direct Discovery. It is used todefine the authorisation policy per PLMN for ProSe Direct Discovery (forPublic Safety and non-Public Safety) and communication (for PublicSafety only) between UE and ProSe Function.” There can be multiplerelationships with 3rd party application service providers for ProSeeach having a 3^(rd) party application DNN 306A (one shown in FIG. 3A).

In the embodiment of FIG. 3B, in which the DDNMF 136 is collocated withthe AF 135 on the DNN 302B, the PC2 interface is supported internallyand the DDNMF 136 PC3 interface towards the UE 110B and PC1 interfacebetween application server (a part of DNN) with UE 110. The DDNMF 136acts as a network function if it needs to utilize service operationsprovided by other network functions (described above).

As noted above, current UE route selection policy (URSP) rules do notidentify which service(s) apply to a particular UE. As such, the UE isleft to determine for itself which are applicable. However, for ProSerules/policies, a policy field of “00000100 ProSe” may be used. ProSerules may be pushed to UE(s) supporting ProSe features. The 5G corenetwork 130 would provide ProSe rules to UE(s) which have ProSeinformation element (IE) set to 1 in a registration request. Table 1shows a list of ProSe path selection and switching (PSS) policies/rulesthat may be created by the PCF (e.g., PCF 134) in response to a requestby the AF 135.

TABLE 1 PSS Policies Policy Type Policy Values Impact PC5 or Uu PolicyPC5/Uu Policy valid for Uu or PC5 Timing Session Validity Timer Time inSeconds Session validity, switch request for session Criteria aftercurrent session Keep Alive Timer Time in Seconds Timer after whichcommunication renewal needed Backoff Timer Time in seconds Backoff timerto avoid repetitive switching between PC5 & Uu Policy Validation Time inSeconds Validity of current policy (Can be different from AF) PrivacyConfig Privacy Service & Timer Configuration & Timer for privacy for L2-config Location Authorized PLMN PLMN ID/SNPN ID Authorized PLMN or SNPNID for validity Criteria of other listed policies Supporting Area in AMFTA/RAN/RA Tracking of UE in AMF for policy validity GeographicalValidity Latitude & Longitude range Geographical Location for PolicyValidity QoS Range Range in Meters Range to switch in and out of PC5Criteria QoS Mapping Rules GFBR/MFBR/AMBR QoS mapping rules forinterface QoS Authorized RAT LTE/NR RAT supporting this policy SignalThreshold dBm Signal threshold for path switching Frequency/GeographicMHz Use of frequency limited to a geographical Area area SeamlessOffload Seamless/Non-Seamless Whether or not buffering is needed forhandover between PC5 & Uu Service Subscription Type Model, Multicast, UERequest/announcement type Criteria Emergency Data Type IP/Non IP IP typeor non-IP type data transfer on interface Service Identifiers Groupcast,Broadcast, Commercial, Public Safety or MBS service Unicast SpecialService Type URLLC/IIoT Identifies special application like URLLC orIIoT device Group Restriction Application Function ID In case groupaccess is restricted to an Application ID Authorization Allowed 1-1,1-Many, UE to Relay Operation Type Relay UP NSSAI/DNN User Plane with NWSlice or DN

It should be noted that all or a subset of these policies may beutilized for a given ProSe application session. Although the policies inTable 1 are mostly self-explanatory, a brief description of some ofthese policies will now be made for further clarity and to expound ontheir impact/relationship with ProSe sessions.

The Session validity timer policy dictates how long a UE can remain in aPC5 session with another UE (or UE to network relay). The Keep alivetimer policy dictates a time period after which the UE will need to senda keep alive activity transmission to the DDNMF node through the PC3interface or other UE (UE to network relay) to let the NW know that theUE is still connected to another UE using PC5. That is, the UE isinforming the NW that the UE is still an active UE and should not bedisregarded by the NW. The Backoff timer policy sets a limit on thenumber of times a UE can send a request on a single interface. In casethere are 2 UEs that are near the maximum distance in which ProSe canfunction, if one of the UEs is idle, it is possible that not much willbe affected. However, if data is exchanged between the 2 UEs, then thequality of service (QoS) may be negatively impacted. As such, the UEthat connects to the other UE (the relay) via PC5 will switch over to Uuto connect to the RAN. At some point however, that UE will try to switchback to proximity mode (PC5). To avoid this back and forth, the backofftimer limits the UE to a specific number of requests on the sameinterface (PC5 or Uu). The Policy validation policy places a timeconstraint on the validity of the policy. After the expiration of thistime period, the UE may need to switch between interfaces or request anew policy/policy update.

The Authorized PLMN policy dictates in which public land mobile network(PLMN) and/or standalone non-public network (SNPN) these ProSe PSSpolicies are valid. The Supporting Area in AMF policy limits a UE'sability to use ProSe to a specific RAN area, thus preventing the UE fromusing ProSe on another AMF or using other policies on another AMF andPCF. The Geographical validity policy defines a geographical area withinwhich a UE may use proximity services which may include a list oflatitude and longitude. The PSS policy in Table 1 relate to this definedarea. The Signal threshold policy defines a threshold value above whichthe UE can switch to PC5, if the signal on PCF is above the threshold orUu, if the Uu signal is above the threshold. The Freq/geographical areapolicy defines the frequency (licensed or unlicensed spectrum) to beutilized for ProSe communications in a given geographical area. This hasto be provided to the UE as criteria for selecting which frequencies itwill use for the PC5 and Uu interfaces. The Seamless offload policydictates whether seamless or non-seamless offload is supported. Forexample, if the NW is broadcasting and some UEs do not have goodconnection to a RAN, one UE may serve as a relay for other UEs. However,when other UEs move away from the relay or they move into an improvedRAN coverage are, it is necessary to know whether or not buffering isneeded.

The Subscription type policy identifies whether a communication ismulticast or emergency and following Model A, B or both for ProSecommunication. Model A type is an announcement by the UE to otherdevices that the UE is present. In type B, the UE is already aware ofwhat devices are present and asks if any of those devices would like toconnect. Whether or not the NW accepts these models is defined in thesubscription type policy. Multimedia Broadcast Multicast Services (MBMS)or Multicast Broadcast Services (MBS) can be used with ProSe &/oremergency broadcast can be used with ProSe applications. The ServiceIdentifiers policy includes groupcast (only within a specified group),broadcast (to any device that can listen), or unicast (UE to UE).Broadcast may include commercial, public safety, or multicastapplications.

The Special service type policy identifies whether the application is aspecial service type such as, for example, a ultra reliable low latencycommunication (URLLC) application or an industrial internet of things(IIoT) application. There are various special services that may utilizeProSe. For example, for remote surgery, a doctor remotely located from asurgical site (e.g., hospital) connects to the NW via URLLC. One UE atthe surgical site also connects to the NW via URLLC and any otherdevices at the surgical site can connect to that UE via ProSe. Thispolicy would make those devices aware that communications in thissession are URLLC and a QoS would be similarly defined.

The Group restriction policy restricts ProSe applications to a specificgroup (e.g., a specific application ID) by providing applicationfunction IDs. The AF 135 provides this information to the PCF 134 toprovide these policies to the UE 110. The Authorization allowed policyprovides authorization for one-to-one, one-to-many, or UE-to-relaycommunications. One-to-one includes ProSe communications and may be, forexample, URLLC or some other applications that can help UE that is outof coverage connect to the NW. One-to-many may include a UE connectingto multiple UEs to exchange information amongst one another (e.g., forgaming together). UE-to-relay allows a UE to act as relay for connectingother devices to the NW.

The Relay User Plane (UP) policy provides the UE with network sliceselection assistance information (NSSAI) or a DNN on which anapplication is to be used. This policy may also define whether thisdedicated network slice should be used for ProSe applications to connectto the NW. For example, if a UE is a relay for other UEs and the UE usesa particular network slice to connect to the NW, the policy woulddictate whether or not the UE should use the same network slice forconnecting the other devices to the NW or if it should use a differentnetwork slice or a DNN to connect those devices to the NW. The policyalso identifies which network slice the relay should use for the otherdevices (this is provided by AF). Also, once QoS and location criteriaare satisfied, service criteria policies instructs the UE that once therelay is chosen, access a predetermined slice and/or DNN. So, thispolicy is more of an instruction to the UE.

FIG. 4 shows a signaling diagram for PCF-based path selection andswitching policies (from Table 1) initiated by the AF according tovarious exemplary embodiments. It should be noted that, multipleapplications may use various different or the same information beprovided to the UE via these policies.

At 405, the AF 135 initiates a ProSe service specific informationprovisioning. In some embodiments, this request may be triggered by theapplication server (AF 135), forwarded by the DDNMF 136 via a PC2interface, or received from the UE 110 via a PC3/PC1 interface (userplane (UP) interface) based on triggers. In some embodiments, this couldbe due to UE registration and policy association. In some embodiments,this could be due to a UE attempting to access certain ProSeapplications or some application of ProSe becoming necessary (e.g.,relay, extending coverage, etc.) In some embodiments, the AF 135initiates the request because an application server wants to start asession with the UE 110 and inform the UE 110 that it may use theservices provided by the application server. As such, there can bemultiple reasons/triggers for causing the AF to initiate the ProSeservice specific information provisioning at 405.

At 410, the PCF 134 creates the policy based on the PSS policiesdiscussed above with respect to Table 1 for this specific applicationinstance and application ID. For example, policies for NW-assisted pathselection and switching may involve coverage and range, QoS, a timewindow, positioning in the NW, and/or UE location. For example, if theUE moves out of Uu coverage and ProSe discovery by the UE to the NWrelay (another UE) is successful, the UE may switch to the PC5 interfacewith the relay to continue service. The range (distance) between the twoUEs also affects the ability to utilize proximity services. QoS isforwarded from PCF 134 to the UE 110 and the RAN 120 for operation ofthe PC5 and Uu interfaces in case the UE switches between theinterfaces. If the QoS is below a threshold on PC5, the UE 110 mayswitch to the Uu interface if a better QoS is available on the Uuinterface. Likewise, if proximity discovery has occurred and the PC5interface can provide a reliable QoS, then the UE 110 may switch fromthe Uu interface to the PC5 interface.

The PCF 134 may also provide a time window during which the UE 110 mayutilize a ProSe PC5 interface instead of a Uu interface. The UE 110 mayswitch from PC5 to Uu after the designated time window has expired.Likewise, the UE 110 may initiate a Uu to PC5 handover when the time hasbegun in case of a successful proximity discovery. A tracking area (TA)or registration area (RA) list within a PLMN that supports ProSefunctionality may be stored on the PCF 134. If the UE 110 moves out ofan area defined in these lists, the UE 110 should switch from the PC5interface to the Uu interface and may also request a policy update fromthe PCF 134. A ProSe application may also be valid within a limited areadefined by latitude and longitude coordinates. The policies may alsoindicate that a UE operating on the PC5 interface should switch to theUu interface when the UE 110 moves further away from this area. However,the UE 110 may later initiate another request for a policy update aftermaking the switch from PC5 to Uu.

At 415, the policy created by the PCF 134 is forwarded to the AMF 132via an AMPolicyControlUpdate message (to which PCF was previouslysubscribed). At 420, the ProSe service access management policy isforwarded to the UE for this specific application ID and session ID.

FIG. 5 shows a signaling diagram for network-assisted path selection andswitching according to various exemplary embodiments. At 505, atriggering event for path switching or selection occurs. In someembodiments, the triggering event at 505 may be an AF triggering eventthat causes the AF 135 to initiate a ProSe service specific informationprovisioning as explained above with respect to FIG. 4 . In someembodiments, the AF triggering event may be the unavailability of a PC1link between the UE 110 and the application server (AF 135) due to a UEmobility event. In some embodiments, the AF triggering event may be anapplication-requested (e.g., an application or third party provider)multimedia broadcast services (MBS) session to enable an MBS relay tobroadcast content. In some embodiments, the AF triggering event may bean application-requested commercial broadcast to enable a commercialbroadcast pushed to a UE serving as a relay to also be pushed to all UEsserved by the relay. In some embodiments, the AF triggering event may bea third party public safety provider application server sending apolicy/provisioning update to the ProSe AF 135 so that an emergencybroadcast pushed to a UE serving as a relay may also be pushed to allUEs being served by the relay.

In some embodiments, the triggering event at 505 may be a UE triggeringevent. In some embodiments, if a PDU session has not yet beenestablished with the ProSe AF 135, the UE 110 will establish the PDUsession according to a UE configuration such as, for example, using aparticular NW slice or connecting to the ProSe AF 135 for thatparticular application session. In some embodiments, the UE triggeringevent may be due to the inability of the UE serving as the relay todiscover a PC5 interface with a UE in a radio resource control (RRC)idle mode. This would trigger an RRC resume service event or RRCconnection setup service event. In some embodiments, the UE triggeringevent may be due to a wanting to transfer an application session from Uuto PC5 based on proximity discovery. For example, if a first UE isexchanging data with a second UE over the NW and, later, the first UEand second UE are in proximity to one another, one UE may want to switchfrom Uu to PC5.

In some embodiments, the triggering event at 505 may be a UE-triggeredProSe policy provisioning to the AMF 132. In some embodiments, this maybe caused by the expiration of the validity timer indicated in the PSSpolicies, causing the UE 110 to trigger a request to switch to the Uuinterface or request new/updated policies. In some embodiments, theUE-triggered ProSe policy provisioning may be caused by theunavailability of valid parameters, for example, in a geographical areain which the UE is located, or due to some other abnormal situation,which would cause the UE to request updated policies.

In some embodiments, the triggering event at 505 may be a PCF-triggeredpolicy provisioning update. This can be caused by the UE not satisfyingone or more of the PSS policies created by the PCF 134. In someembodiments, this is caused by a UE mobility event such as, for example,the UE moving from one PLMN to another PLMN, which occurs when the UEuses the UE Policy Association Modification procedure initiated by theAMF. In some embodiments, the PCF-triggered policy provisioning updatemay occur when there is a subscription change in the list of PLMNs wherethe UE is authorized to perform ProSe operations over PC5, which isachieved by using the UE Policy Association Modification procedureinitiated by the PCF 134. In some embodiments, the PCF-triggered policyprovisioning update may occur when there is a change of aservice-specific parameter provisioning.

Returning to FIG. 5 , at 510, the UE(s)/relay 110 sends deregistrationrequest or group communication update to the DDNMF 136 using a PC3interface. It should be noted that this request may or may not begenerated depending on which trigger occurred at 505. For example, ifthe trigger was an AF trigger, the UE(s) request may be skipped. Itshould also be noted that this request may depend on the number of UEsand UE communications that exist.

At 515, the DDNMF 136 generates a session update request and forwardsthis request to the AF 135 using the PC2 interface. In some embodiments,the request includes an application ID, a user ID, a session ID andother ProSe session parameters. Regardless of whether the DDNMF is astandalone function or if it is collocated with the AF 135, theconnectivity between the DDNMF 136 and the AF 135 remains the same.

At 520, the AF 135 invokes a traffic influence request for theapplication ID and session ID with request type ProSe discovery orswitch or Policy Change depending on the trigger type at 505 and thenode (UE or AF) at which trigger was generated. As a result, the AF 135initiates traffic influence for path switching and policy changes. At525, the NEF 137 forwards the request to the relevant PCF 134 as PolicyAuthorization Create/Modify/Delete depending on the nature of therequest and switch types (Uu to PC5 or PC5 to Uu), which was receivedfrom the AF 135.

At 530, the UE-specific PSS policy update is generated/modified by thePCF 134. The policy(ies) may be updated based on the PSS policies inTable 1. At 535, the PCF 134 forwards the policy update with PSS Update,application type and other session information to the SMF 131 forfurther processing with a PDU session using the SMPolicy Controlmessage. At 540, an N4 session is modified at the UPF level with thepolicy changes and the UP tunnel is created, modified, torn downdepending on the request type, trigger type, or application type.

At 545, a PDU session update is forwarded to the AMF 132 from the SMF131 for further processing of the request. At 550, the AMF 132 sends anN2 update message to the RAN 120 for updating the Policy at the RANlevel and forwarding the policies to the specific UE 110.

At 555, depending on the state of the UE(s) and existing connections,the RAN 120 can send a paging request within the area in which the UE110 was/is located. If the UE 110 was in idle state or was using PC5,the UE 110 would need to be paged to connect to the RAN 120 via Uu. Ifthe UE 110 was using Uu and wants to switch to PC5, the RAN 120 wouldinitiate an RRC reconfiguration. At 560, as per the policy, state, andtrigger, the switching and selection of the interface (PC5 or Uu) isperformed now at UE(s)/Relay level and a discovery request may beinitiated at this step. However, if the UE 110 is already utilizing thePC5 interface and is switching to the Uu interface at 560, then the RRCreconfiguration request may be initiated (instead of a discoveryrequest).

FIG. 6 shows a signaling diagram for application-assisted path selectionand switching according to various exemplary embodiments. Initially, itshould be noted that if the content provider 602 shown in FIG. 6 isoutside of the 5G NW domain, then this signaling diagram would terminateat the ProSe AF 135. However, in this discussion, it is assumed that thecontent provider 602 is within the 5G NW domain.

At 605, PC1 link monitoring is active between the UE(s) 110 and theapplication server (the AF 135) or the content provider 602. At 610, theUE 110 is in an RRC idle state. However, a PC5 link may be activebetween this UE 110 and a relay (another UE). At 615, conditions for atriggering event may be satisfied at the application server (the AF 135)or the content provider 602 pertaining to a switch from a PC5 to a Uuunicast link or vice versa. At 620, the AF 135 forwards downlink datawith a request type path switch & other content delivery using a PDUsession in the UP. It should be noted that this request may be toperform a unicast operation with Uu or enable a relay operation with aUu to PC5 switch. At 625, this request is forwarded as an N4 message fora session update from the UPF 133 to the SMF 131.

At 630, the NW triggers a service request to page the UE 110 for unicastdelivery. The service request requests that the UE switch from PC5 to Uudepending on whether the UE was unreachable or did not perform linkmonitoring due to an application state. At this point, the NW cantrigger service request or ping the UE 110 to request that the UE 110switch interfaces to receive data from the content provider 602 intendedfor the UE 110. In some embodiments, the NW requests that the UE 110remain on PC5, but start sending the link monitoring request. In someembodiments, the NW requests that the UE 110 use both PC5 and Uuconcurrently, although the UE 110 chooses one interface based on UEpolicy. In some embodiments, the NW may request that the UE switch to Uubecause the data from the content provider 602 may be transmittedthrough the RAN 120.

At 635, the UP path switch between the UE 110 and application server orcontent provider is updated after a delivery link is established. At640, the UE 110 performs the path switching based on the UE's preference(based on PSS policies).

FIG. 7 shows a signaling diagram for a UE-requested policy provisioningupdate according to various exemplary embodiments.

At 705, a UE triggering event occurs. The triggering event may be basedon any of the PSS policies of Table 1 or any other policies beingtriggered at the UE 110 such as, for example, the UE-triggering eventsdiscussed above. In some embodiments, the UE triggering event may besomething as simple as initiating an application. At 710, the UE sendsthe UE policy provisioning request, including the UE policy container(ProSe PSS Policy Provisioning Request), to the AMF 132.

At 715, the AMF 132 sends the update request(Npcf_UEPolicyControl_Update) to the PCF 134, including the UE PolicyContainer received from UE 110 at 710. At 720, the UE policydelivery/update procedure defined in 3GPP TS 23.502 section 4.2.4.3 istriggered. The PCF 134 may determine whether or not new policies areused. If the PCF 134 determines that there are no new UE policy updatesfor this session, then ProSe are not available to the UE for thisapplication and the UE 110 uses the Uu interface to connect to the NW.If, however, the PCF 134 determines that there are new policies, it canupdate the UE at 720.

FIG. 8 shows a signaling diagram for a networks data analytics function(NWDAF)-based path selection and switching analytics and predictionsaccording to various exemplary embodiments. At 805, the AF 135 maysubscribe to the analytics and predictions request from the NWDAF 802 toprovide details which might help in generating efficient triggers andpolicies for respective UE(s). That is, the AF 135 requests that theNWDAF 802 provide analytics on the basis of specific functions such as,for example, coverage enhancement with a relay, congestion mitigation,data that is application-specific (e.g., which applications do and donot require ProSe). In some embodiments, this subscription request mayinclude the application type, the application ID, and the interfacesupported. At 810, the NWDAF 802 subscribes to the UE policies,application policies, and triggers from the PCF 134.

In some embodiments, this subscription request may include PSS policyand application instances. At 815, the NWDAF 802 further subscribes toUE(s) mobility information from the AMF 132 (e.g., where the UE 110was/is, where the UE 110 moves, in which registration area or trackingarea has the UE been, etc.) to generate patterns with respective UE IDsto map for congestion mitigation and efficient analytics provisioningfor different times of day. In some embodiments, this subscriptionrequest may include UE app IDs and UE(s) mobility information. In someembodiments, the NWDAF 802 may request this information from the UE 110.However, this would require the UE to accept to share application andlocation data with the NWDAF.

At 820, the NWDAF 802 prepares the analytics for the data with furtherinputs from an operations, administration and management/maintenance(CAM). At 825, the NWDAF 802 performs data analysis based on UE mobilitypatterns, policies, application types and interfaces used. At 830, theNWDAF 802 forwards the analysis to the AF 135. In some embodiments, theanalysis may include UE interface usage, time(s) of day, applicationutility, interface (PC5/Uu) usage details, congestion mitigation, andrelay enablement/UE group communication patterns. At 835, the AF 135 canrenegotiate/change the PSS policies based on the analysis andpredictions received at 830, depending on UE mobility, the time of day,and interface usage. In some embodiments, the AF 135 may also modify thetriggers discussed above.

Although this application described various embodiments each havingdifferent features in various combinations, those skilled in the artwill understand that any of the features of one embodiment may becombined with the features of the other embodiments in any manner notspecifically disclaimed or which is not functionally or logicallyinconsistent with the operation of the device or the stated functions ofthe disclosed embodiments.

It is well understood that the use of personally identifiableinformation should follow privacy policies and practices that aregenerally recognized as meeting or exceeding industry or governmentalrequirements for maintaining the privacy of users. In particular,personally identifiable information data should be managed and handledso as to minimize risks of unintentional or unauthorized access or use,and the nature of authorized use should be clearly indicated to users.

Those skilled in the art will understand that the above-describedexemplary embodiments may be implemented in any suitable software orhardware configuration or combination thereof. An exemplary hardwareplatform for implementing the exemplary embodiments may include, forexample, an Intel x86 based platform with compatible operating system, aWindows OS, a Mac platform and MAC OS, a mobile device having anoperating system such as iOS, Android, etc. In a further example, theexemplary embodiments of the above described method may be embodied as aprogram containing lines of code stored on a non-transitory computerreadable storage medium that, when compiled, may be executed on aprocessor or microprocessor.

It will be apparent to those skilled in the art that variousmodifications may be made in the present disclosure, without departingfrom the spirit or the scope of the disclosure. Thus, it is intendedthat the present disclosure cover modifications and variations of thisdisclosure provided they come within the scope of the appended claimsand their equivalent.

What is claimed:
 1. The non-transitory computer readable storage mediumcomprising a set of instructions, wherein the set of instructions whenexecuted by a processor cause the processor of a user equipment (UE) toperform operations, comprising: determining that a triggering event hasoccurred, wherein the triggering event is based on a set of proximityservices (ProSe) path selection and switching (PSS) policies;transmitting a setup or update request to a direct discovery namemanagement function (DDNMF) of a 5G core network; receiving UE-specificpolicies based on the set of ProSe PSS policies; and switching from oneof a PC5 interface or a Uu interface to another one of the PC5 interfaceor the Uu interface.
 2. The non-transitory computer readable storagemedium of claim 1, wherein the triggering event is a UE-triggeringevent.
 3. The non-transitory computer readable storage medium of claim1, wherein the triggering event is an application function(AF)-triggering event.
 4. The non-transitory computer readable storagemedium of claim 1, wherein the ProSe PSS policies are created by apolicy control function (PCF) of the 5G core network in response to arequest by an AF of the 5G core network.
 5. The non-transitory computerreadable storage medium of claim 4, wherein the ProSe PSS policiesinclude at least one of timing criteria, location criteria, QoScriteria, and service criteria.
 6. The non-transitory computer readablestorage medium of claim 1, wherein the UE-specific policies received arean update to policies already being used by the UE.
 7. Thenon-transitory computer readable storage medium of claim 1, wherein theDDNMF is a standalone function on the 5G core network.
 8. Thenon-transitory computer readable storage medium of claim 1, wherein theDDNMF is collocated with an AF of the 5G core network.
 9. Thenon-transitory computer readable storage medium of claim 1, wherein theUE-specific policies include an authorization for the UE to serve as arelay for connecting one or more other UEs to a 5G new radio (NR)network.
 10. A user equipment (UE), comprising: a transceiver configuredto connect to a next generation nodeB (gNB) and further UE; and aprocessor configured to: determine that a triggering event has occurred,wherein the triggering event is based on a set of proximity services(ProSe) path selection and switching (PSS) policies; transmit a setup orupdate request to a direct discovery name management function (DDNMF) ofa 5G core network; receive UE-specific policies based on the set ofProSe PSS policies; and switch from one of a PC5 interface to connectwith the further UE or a Uu interface to connect to the gNB to anotherone of the PC5 interface or the Uu interface.
 11. The UE of claim 10,wherein the triggering event is a UE-triggering event.
 12. The UE ofclaim 10, wherein the triggering event is an application function(AF)-triggering event.
 13. The UE of claim 10, wherein the ProSe PSSpolicies are created by a policy control function (PCF) of the 5G corenetwork, wherein the ProSe PSS policies include at least one of timingcriteria, location criteria, QoS criteria, and service criteria.
 14. TheUE of claim 13, wherein the PCF creates the ProSe PSS policies inresponse to a request by an AF of the 5G core network.
 15. The UE ofclaim 10, wherein the UE-specific policies received are an update topolicies already being used by the UE.
 16. The UE of claim 10, whereinthe DDNMF is a standalone function on the 5G core network.
 17. The UE ofclaim 10, wherein the DDNMF is collocated with an AF of the 5G corenetwork.
 18. The UE of claim 10, wherein the UE-specific policiesinclude an authorization for the UE to serve as a relay for connectingone or more other UEs to a 5G new radio (NR) network.
 19. An integratedcircuit configured for use in a user equipment (UE), comprising:circuitry configured to determine that a triggering event has occurred,wherein the triggering event is based on a set of proximity services(ProSe) path selection and switching (PSS) policies; circuitryconfigured to transmit a setup or update request to a direct discoveryname management function (DDNMF) of a 5G core network; circuitryconfigured to receive UE-specific policies based on the set of ProSe PSSpolicies; and circuitry configured to switch from one of a PC5 interfaceto connect with another UE or a Uu interface to connect to a nextgeneration NodeB (gNB) to another one of the PC5 interface or the Uuinterface.
 20. The integrated circuit of claim 19, wherein thetriggering event is one of a UE-triggering event or an applicationfunction (AF)-triggering event.